#pragma once

/** \brief Mersenne Twister pseudorandom number generator.

Ripped from internet and modified. Original license see below.

A C-program for MT19937, with initialization improved 2002/1/26.
Coded by Takuji Nishimura and Makoto Matsumoto.

Before using, initialize the state by using init_genrand(seed)  
or init_by_array(init_key, key_length).

Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
All rights reserved.                          

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. The names of its contributors may not be used to endorse or promote 
products derived from this software without specific prior written 
permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


Any feedback is very welcome.
http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html
email: m-mat @ math.sci.hiroshima-u.ac.jp (remove space)

*/

class MT19937{
private:
	/* Period parameters */  
	static const int N = 624, M = 397;
	static const unsigned int MATRIX_A = 0x9908b0dfUL;   /* constant vector a */
	static const unsigned int UPPER_MASK = 0x80000000UL; /* most significant w-r bits */
	static const unsigned int LOWER_MASK = 0x7fffffffUL; /* least significant r bits */

	unsigned long mt[N]; /* the array for the state vector  */
	int mti;
public:
	/** initializes mt[N] with a seed */
	void Init(unsigned int s);

	/** initialize by an array with array-length */
	/** \param init_key is the array for initializing keys */
	/** \param key_length is its length */
	/** \note slight change for C++, 2004/2/26 */
	void Init(unsigned int init_key[], int key_length);

	/** generates a random number on [0,0xffffffff]-interval */
	unsigned int Rnd();
};

